Human substance P receptor lacking the C-terminal domain remains competent to desensitize and internalize.
Human substance P receptor lacking the C-terminal domain remains competent to desensitize and internalize.
复制标题
缺乏 C 末端结构域的人 P 物质受体仍然具有脱敏和内化的能力。
DOI：
10.1046/j.1471-4159.2003.01577.x
复制
发表时间：
2003
影响因子：
4.7
通讯作者：
Kwatra,MadanM
中科院分区：
文献类型：
--
作者：
Richardson,MarkD;Balius,AnastasiaM;Yamaguchi,Keisuke;Freilich,EmilyR;Barak,LarryS;Kwatra,MadanM
P物质受体(SPR)及其自然产生的剪接变异体，缺少C末端尾巴，在脑和脊髓中被发现。C末端截短的SPR是否像全长SPR一样不敏感是有争议的。我们使用多种方法来确定人类SPR(HSPR)和C末端截短的突变体hSPRΔ325在脱敏和内化方面是否不同。在表达hSPRPKCGFP 325或hSPR的HEK293细胞中，用三磷酸肌醇蓄积或将共表达的ΔII-β瞬时转位到质膜来衡量SP对这两种受体的脱敏作用是相似的。此外，β-arrestin 1或2-gfp(βarr1-gfp或βarr2-gfp)转位到质膜，受体内化也相似。然而，热休克蛋白受体和热休克蛋白受体Δ325在其磷酸化和形成含β-arrestin的内吞囊泡的能力上有所不同。与hSPR不同，hSPRΔ325在完整的HEK293细胞中没有被磷酸化到可检测的水平，并且hSPR形成包含βarr1-gfp或βarr2-gfp的囊泡，而hSPRHEK293 25不与Δarr1-gfp形成任何囊泡，并且与βarr2-gfp形成更少的囊泡。我们得出结论，截短的hSPR经历了激动剂依赖的脱敏和内化，而没有检测到受体磷酸化。
Substance P receptor (SPR) and its naturally occurring splice‐variant, lacking the C‐terminal tail, are found in brain and spinal cord. Whether C‐terminally truncated SPR desensitizes like full‐length SPR is controversial. We used a multivaried approach to determine whether human SPR (hSPR) and a C‐terminally truncated mutant, hSPRΔ325, differ in their desensitization and internalization. In HEK‐293 cells expressing either hSPRΔ325 or hSPR, SP‐induced desensitization of the two receptors was similar when measured by inositol triphosphate accumulation or by transient translocation of coexpressed PKCβII‐GFP to the plasma membrane. Moreover, translocation of β‐arrestin 1 or 2‐GFP (βarr1‐GFP or βarr2‐GFP) to the plasma membrane, and receptor internalization were also similar. However, hSPR and hSPRΔ325 differ in their phosphorylation and in their ability to form β‐arrestin‐containing endocytic vesicles. Unlike hSPR, hSPRΔ325 is not phosphorylated to a detectable level in intact HEK293 cells, and whereas hSPR forms vesicles containing either βarr1‐GFP or βarr2‐GFP, hSPRΔ325 does not form any vesicles with βarr1‐GFP, and forms fewer vesicles with βarr2‐GFP. We conclude that truncated hSPR undergoes agonist‐dependent desensitization and internalization without detectable receptor phosphorylation.